Question

describe user;

 id       int(1)       NO    'PRI'  0             
 name     'varchar'(20)  YES        NULL           
 address  'varchar'(20)  YES        NULL          
 class    int(2)       YES        NULL           
 DOB      date         YES        NULL           
 created  date         YES        NULL 


describe 'marklist'
+-------------+-------------+------+-----+---------+-------+
| Field       | Type        | Null | Key | Default | Extra |
+-------------+-------------+------+-----+---------+-------+
| id          | int(1)      | NO   |     | 0       |       |
| subject     | varchar(10) | YES  |     | NULL    |       |
| 'markscored'| int(2)      | YES  |     | NULL    |       |
| 'outof'     | int(2)      | YES  |     | NULL    |       |
| 'userid'    | int(2)      | YES  |'NUL'| NULL    |       |
+-------------+-------------+------+-----+---------+-------+

这是给出的两个表，从这两个表中我需要输出为：

|name |class|biology|chemistry|physics|outoftotal|totalmarkscored|percentage|
+-----+-----+-------+---------+-------+----------+---------------+----------+
|arun | 5   |  45   |  42     |  40   |  150     | 127           |84.6      |

请使用两个表user和marklist＆＃39;

给我一个查询以获得上述输出

Answer 1

顺便说一句，int（2）有＆＃39; 150＆＃39;这很奇怪。

＆＃39;用户＆＃39;在sql中也是一个保留字，所以不要使用它pls

SELECT u.name,u.class,
(SELECT SUM(subject) FROM marklist WHERE subject LIKE 'biology') AS biology,
(SELECT SUM(subject) FROM marklist WHERE subject LIKE 'chemistry') AS chemistry,m.outof AS outoftotal,m.markscored AS     
totalmarkscored,m.markscored/m.outof*100
FROM user u, marklist m
WHERE u.id=m.id

Answer 2

在执行修改后的查询后感谢MVCNoob： SELECT u.id，u.name，u.class，（SELECT SUM（markscored）FROM marklist WHERE subject LIKE＆＃39; biology＆＃39; AND u.id = m.id）AS biology，（SELECT SUM（markscored）FROM marklist WHERE subject LIKE＆＃39; chemistry＆＃39; AND u.id = m.id）AS chemistry，（SELECT SUM（markscored）FROM marklist WHERE subject LIKE＆＃39; physics＆＃39; AND u.id = m.id）AS physics，（SELECT SUM（markscored）FROM marklist WHERE u.id = m.id）AS total，（SELECT SUM（outof）FROM marklist WHERE u.id = m.id）AS outof，（（SELECT SUM（markscored）FROM marklist WHERE u.id = m.id）/（SELECT SUM（outof）FROM marklist WHERE u.id = m.id）* 100）as p 来自你，marklist m WHERE u.id = m.userid = 1; ，我得到一个输出： + ------ + ------ + ------- + --------- + ----------- + ----- ---- + ------- ------- + + --------- + | id |名字|班级|生物学|化学|物理|总计| outof | p | + ------ + ------ + ------- + --------- + ----------- + ----- ---- + ------- ------- + + --------- + | 1 |阿伦| 6 | 37 | 48 | 48 | 133 | 150 | 88.6667 | | 1 |阿伦| 6 | NULL | NULL | NULL | NULL | NULL | NULL | | 1 |阿伦| 6 | NULL | NULL | NULL | NULL | NULL | NULL | + ------ + ------ + ------- + --------- + ----------- + ----- ---- + ------- ------- + + --------- + 集合中的3行（0.00秒），这里arun正在重复pls请让我查询以避免重复感谢你

加入两个表以生成给定的输出

2 个答案: